Gout After Living Kidney Donation: A Matched Cohort Study

5 years ago

Gout After Living Kidney Donation: A Matched Cohort Study

In the general population, high serum uric acid concentration is a risk factor for gout. It is unknown whether donating a kidney increases a living donor’s risk of gout as serum uric acid concentration increases in donors after nephrectomy.

Study Design

Retrospective matched cohort study using large health care databases.

Setting & Participants

We studied living kidney donors who donated in 1992 to 2010 in Ontario, Canada. Matched nondonors were selected from the healthiest segment of the general population. 1,988 donors and 19,880 matched nondonors were followed up for a median of 8.4 (maximum, 20.8) years.

Predictor

Living kidney donor nephrectomy.

Outcomes

The primary outcome was time to a diagnosis of gout. The secondary outcome in a subpopulation was receipt of medications typically used to treat gout (allopurinol or colchicine).

Measurements

We assessed the primary outcome with health care diagnostic codes.

Results

Donors compared with nondonors were more likely to be given a diagnosis of gout (3.4% vs 2.0%; 3.5 vs 2.1 events/1,000 person-years; HR, 1.6; 95% CI, 1.2-2.1; P <0.001). Similarly, donors compared with nondonors were more likely to receive a prescription for allopurinol or colchicine (3.8% vs 1.3%; OR, 3.2; 95% CI, 1.5-6.7; P =0.002). Results were consistent in multiple additional analyses.

Limitations

The primary outcome was assessed using diagnostic codes in health care databases. Laboratory values for serum uric acid and creatinine in follow-up were not available in our data sources.

Conclusions

The findings suggest that donating a kidney modestly increases an individual’s absolute long-term incidence of gout. This unique observation should be corroborated in future studies.

Publisher URL: www.sciencedirect.com/science

DOI: S0272638615004849